One in 10 Garda superintendents has faced internal inquiries over the past three years, the Irish Independent has learned.

And others are at the centre of investigations carried out on behalf of the Garda Ombudsman Commission.

Some 16 superintendents have been investigated internally since 2014 and three of those inquiries are still ongoing.

The increase has been partly attributed to the growing emphasis on oversight, with superintendents being held responsible for the behaviour of their staff.

But there is also serious concern at the tougher line being taken by garda authorities over contacts between officers and journalists.

A number of those inquiries have been initiated following complaints to the Ombudsman from politicians about so-called leaks to the media.

The unprecedented level of action has led to unease among the 166 superintendents in the force as they do not have access to funding for legal backing.

This is in contrast to their colleagues in the lower ranks of the Garda or their counterparts in the UK. It is understood that at least 10 of the officers have sought advice from their representative association.

Superintendents said they were very concerned at the stance taken by the authorities over the alleged leaks.

One officer told the Irish Independent: "On the one hand, we are encouraged to be as open as possible with the media, without revealing any details of an investigation that might hinder it in the future.

"But, on the other, superintendents are being targeted for talking to journalists even when it is clear they can do so under the accepted guidelines and they are not discussing State secrets," the officer added.

Several officers were placed under investigation because the authorities examined their phone records and found the numbers of journalists there.

The most worrying case involves a superintendent who had permission to speak regularly to journalists but was subsequently suspended from duty as inquiries were carried out.

The officer was arrested in April last year and held for questioning in a Dublin garda station. A file was sent to the DPP, whose office then sought additional information, and he is still awaiting a decision on whether he is to face any criminal charges.

That case has been continuing for 16 months and, in the meantime, his period of suspension has been extended again until November while he remains at home on part pay.

An Garda Síochána said that it did not comment on internal disciplinary inquiries but it was cognisant of its obligation to inquire into all matters that came to the attention of the organisation. It said the Ombudsman Commission also had a role to conduct inquiries under the Garda Síochána Acts.

It said welfare supports and services were available to all members of the force.